Automatic flow control means



Feb. 6, 1940. c, H. Mm; 2,189,330

AUTOMATIC FLOW CONTROL MEANS Filed Dec. 15, 1958 3 Sheets-Sheet 1 Fig.1

INVENTOR. 5 CHARLES/v. SM/v'H ATTORNEY Feb. 6, 1940. c Sm-m AUTOMATICFLOW CONTROL MEANS 3 Sheets-Sheet 2 M ww ggw m a R A TTORNEY Feb. 6,1940. c sMlTH 2,189,330 AUTOMATIC FLOW CONTROL MEANS Filed Dec. 13, 19385 Sheets-Sheet 5 INVENTOR. HA R1. 55/). 5/4/71 4 A TTORNEY Patented Feb.6,1940

i STATES rTEN-T OFFICE Charles H. Smith, PortlandfOreg. I ApplicationDecember 13, I938, Serial No. 245,408 I v 10 claims, (01. 137- 8) I Thisinvention relates to automatic flow control means-for hydraulic systemsand is peculiarly adapted for use in controlling the amount of flow fromlaterals into a main trunk sewer in 5 sewage disposal systems in largecities and it will be so illustrated and described for the purpose ofthis'disclosure. t 1

It isan object of the present invention to devise mecl'ianisin toregulate fiow volume in arelatively predetermined proportion from aplurality of laterals into a trunk line, insuch manner that each willcontribute its predetermined part of the whole capacity of the trunkline, regardless of the hydraulic head tending to dump the entire 5flowage of. one lateral into the trunk, at the expense of carryingcapacity to be apportioned to other laterals further along the trunktowards.

the point of final disposal.

In sewagadisposal systems the gathering of sewage "from criginalsourcesisaccomplished by branched lateral systems of pipes, laid to a hydraulicgradient according to limitations imposed by topography. For example, ifa considerable area to be drained lies along the bank of a river, ;sayfor a distance ot several iniles'thelriver grade forms the naturaldrainage outlet. for that district. The laterals, however, owing tosurface irregularities, must-in general benormal to the river, reachingit at a number of separated points 0 along its bank, the logical andonly place for the trunk sewer if gravity flow is to be depended upon toany extent. Maximum storm-water conditions usually connote overfiow, asclear as may be from the semi-solids. 3 l

': As is well-known, the semi-solids from the laterals will tend to thebottom of the laterals, especially if an enlargement or basin beprovided to check the velocity of the flow at the terminus or point orjuncture with the trunk. Overflow outlets will be provided to dispose ofstorm water surplus but it is very important that each lateral havereserved its allotted portion of the whole capacity of the trunk, thatthe semi-solids shall for the most part at least go tothe trunk; and not5* into the river through the overflow, during excess water periods. 7

Apparatus to admirably'accomplish the functions hereto-fore set out areillustrated in the accompanying drawings and described in the spec- 50ificatlon, but are not intended as limiting the invention to the oneembodiment, the; scope of the invention to be ascertained from theclaims which follow. a Drawings of the particular embodiment chosen toillustrate the invention herewith, are in three assumed to be about thecenter of the drainage sheets consisting of six related figures, asfollows:

Fig. I is a vertical sectionof a preferred form, t to be described indetail l t L Fig. 11 is a plan view of FigrI; 5 t Fig. III is a sectionon the line III-J11, Fig. I; Fig. IV is a section taken on the lineIV--IV of Fi I; l

Fig'V is a section on V-V of Fig. I; and Fig. VI is a section on VIVI,Fig. I. j ,l'u In the drawings, i is a conduit communicating withanadjacent trunksewennot shown, and 2 is a lateraLthe entire flow fromwhich is to be delivered to the conduit I, under normal conditions, and3 is a valve opening through which 15 the now takes place. Underexpected normal conditions, the valve 4 will be at rest'in about theposition shown, that is to allow full capacity of the opening 3. r

This lateral 2 will be only one of a number of 20 lines that aredesigned to discharge into the trunk and for purpose of illustration itwill be district served. Thus under abnormal conditions, if the lateralsabove it have not been con- 25. trolled, the trunk carrying capacity,will have been satisfied by laterals discharging from -a higher level;hence the particular one shown would have to overflow its entire volume.

Each of the other laterals will, however, have 3!), beenequipped withcontrols similar though per- 1 haps. varying in the sizeof the valveopening 2 and its cooperating valve 2. Mechanism to operate the valveflow and deliver apredetermined quantity of fiow to the conduit i willnow be described. 3;:

The lateral discharges into the chamber 6 which breaks the flowvelocitygjtending to keep the semi-solid parts of the flow at thebottom.

As the flow begins to exceed thecarrying capac ity of the valve opening3, a hydraulic head devel- 40 ops in the chamber 6, being reflected inthe float well I, in communication therewith by the screenedopening 8. y

. A float 9 is provided with guides such as H],

H and E2. The fioat rises with the liquid in the well l. The float Q isprovided with a central opening in which is fixed a plural thread nut l3which is an easy fit on the threaded shaft M, the

threads in this case being quadruple. I

The shaft I4 is mounted revolubly in the lower 7 bearing l5 and theupper bearing l6 and carries a rigidly fixed worm ll that engages withthe double roller head It, made rigid with the lever Hi. It will benoted that the worm l1 andr the double roller head I8 have the samerelationship as a relative low pitch worm with sector of a worm gear,that is the worm runs the gear easily but the locking characteristic ofa worm and gear is present to oppose revolution from oppositely actingforces. This constitutes a very effective irreversible reducing motionbetween the float and the valve.

The thread of the worm l l is made with a differential or changing pitchto give a faster motion when the valve 4 starts to close than when it isfurther along towards closure, because the friction of fluid passingbetween the valve 4 and the valve seat 4a increases as the square of thevelocity; hence a uniform closing of the valve will not result in amaintained volume which is corrected by the variable pitch. Thisvariable pitch must be computed for each size of valve and seat;therefore the indication is diagrammatic and suflicient for the engineerskilled in such design when his attention is called to its necessity.

The lever I9 is fulcrumed on the standard 20. which is movably attachedto the base 2| by cap screws 22, or other preferred means. It passesthrough the sleeve 23, provided with trunnions 2 3 rockably engaged bythe standard 20; hence-the relative length of the two arms of the leverIt? may be changed for adjustment to operate valves 4 of varying size.

The operated arm of the lever |9a is pivotally connected .to the valvestem 25 by the trunnioned sleeve 26 which is quite similar to the oneshown at 23. The valve stem 25 is constrained to lineal verticalmovement by suitable bearings such as 21 and 28; hence any rise of thefloat 9 causes the worm l! to turn proportionately to such rise, whichturning movement is translated into a downward movement of the valvestem 25, reducing the area of the annular opening 311', carefullydesigned to have the same carrying capacity as the opening 3 when therelative position of the valve 4 is as shown. If the apparatus isproperly designed, each increment of increase of hydrostatic head overthe valve 4 will be reflected as a corresponding rise ofthe float 9,which, as explained, will be translated into a relative closing movementof the valve 4 with respect to the opening 3a and the actual flowtherethrough will be the same within close limits whether the float isup, down or in any intermediate position. The actuating mechanism is soproportioned that complete closure of the valve 4 never occurs.

Counterbalance means for the valve stem 25 is shown by the weights 30attached tocables 3i passing over the pulleys 32 and attached to theclamp 33.

Since the buoyancy lift of the float 9 will ordinarily be less than itsweight, an equalizer is shown as the drum 35, the cable 36, the pulley31 and the counterweighttfi so arranged as to assist the turning momentof the shaft M when the hydrostatic head tends to raise the float 9.

The exemplification' as described is for a sewage system. but quiteobviously it can be arranged without substantial change to deliver arelatively fixed amount of Water from a main irrigation ditch to alateral, with a varying head in the main ditch. It has many otherapplications which will be at once apparent to the hydraulic engineer.

The devices of the'present exempliflcation of the invention have beenexplained with a considerable attention. to detail, sothat the art mayfully understand the principle of operation, but it'is not intended asmarkingthe boundaries of the claims.

What I claim as new and desire to secure by Letters Patent is- 1.Automatic flow control means comprising a valve, a lever that isarranged to control said valve and a float that is arranged to actuatesaid lever, characterized by a transmission between the float and thelever that includes a worm. revoluble by movement of thefloat and a wormgear sector that is in engagement with the worm.

2. In a flow control apparatus of the character described wherein avariable hydrosatic head above an outlet orifice is controlled forstable delivery capacity, a supply conduit, a receiving conduit, adivisional wall therebetween that is provided with an orifice, a valvepositioned to vary the eflective area of said orifice, a float chamberconnected to the receiving conduit, a float that is movable thereinunder the influence of liquid level, speed reducing transmissionsbetween the float and the valve that are effective sensitive tohydraulic head above said valved conduit and a transmission between thevalve and the float that is in part a differential reducing motiondevice that is effective to move the valve to maintain substantiallyuniform discharge capacity thereof under varying hydraulic heads.

4. In a flow control means, a chamber that is positioned to receive flowfrom a conduit, a needle valve adjacent the bottom of the chamber, a conduit positioned to receive discharge from the valve, a float wellpositioned adjacent the said chamber that is in hydraulic communicationtherewith, a float in said well, means constraine ing the float tovertical reciprocating movement. a threaded nut carried by said float, athreaded shaft that is rotatable by said nut and transmission meansbetween the shaft and the valve that are effective to transform rotativemotion thereof into varying reduced reciprocating motion of the valve.

5. Float control means for reciprocating a valve in reduced differentialmovement with re spect to the movement of the float, comprising a meanslimiting movement of the float to reciprocating vertical motion, arotative shaft, helical cooperative connections between the float andthe shaft that are effective to rotate the shaft when the float moves, awormof varying pitch made rigid with the shaft, a worm gear sectorengaged with the worm, a needle valve, and transmissions operativelyarranged between the sector andthe valve that are effective to move thevalve proportionately to the movement of the sector. v

6. A float controlled valve for a water system comprising a valve seatmember provided with an opening, a cooperative valve, a float positionedadjacent said valve that is sensitive to supply volume for said valve,anddifferential transmissions between the said float and said valve thatinclude a worm rotatable under the influence of the float and a wormgear sector that is in engagement with said worm, whereby the flowthrough the valve is substantially constant under varying hydrostaticheads thereabove.

'7. A float controlled valve for a water system comprising a valve seatmember provided with an opening, a cooperative valve, a float positionedadjacent said valve that is sensitive to supply volume for said valve,transmissions between the'said float and said valve that include a wormrotatable under the influence of the float and a wormgear sector that isin engagement with said worm, characterized by a thread of differentialpitch on the'worm to compensate for varying friction coeflicients ofwater passing throughthe valve. I

8. Flow control means comprising a valved flow portal, a floatpositioned adjacent the portal on the intake side thereof, guide meansfor restricting float movement to a verticalplane, a

rotative member operatively' connected to said float that is rotatablein synchronism with the movement of the float and a differentialtransmission mechanism operatively arranged between ;of the float, a'differential thread on the worm, a worm gear sector engaged with thethread of the worm. and transmissions operably connected to the saidsector that are effective to differentially vary the flow volume throughthe portal underthe influence of the thread.

10. In hydraulic flow control means, a valve,

a float that is positioned to be sensitive to the a supply head abovesaid valve and reducing transmission mechanisms between said float andsaid valve that tend. to close the valve as the head above it increases,characterized by a differential portion of said transmission that iseffective to compensate forythe difference in flow friction through-thevalve as the same tends to be limited by action of the float.

CHARLES H. SMIETH. 2s

